The present invention relates to a photographic printer, and more particularly to a photographic printer in which a film carrier is shifted by 90 degrees in accordance with a film frame size so as to change a direction of transportation of the film.
Along a printing optical path of a photographic printer between a light source and a photographic paper, there are disposed, in order, a mirror box for making uniform the intensity of a printing light, a film carrier for guiding and holding a photographic film, and a printing lens. The mirror box consists of a square shaped, open ended mirror tube with mirrored inner walls and diffusion plates attached to the top and bottom of the mirror tube. A film mask, having an aperture suitable for a frame size of a photographic film is set on the film carrier. For example, for a 135 type photographic film a first film mask formed with a full-size aperture, and a second film mask, formed with a half-size aperture, are formed. There also is a known film mask formed with both full-size and half-size apertures, one of which is set on the printing optical path in accordance with the frame size of a photographic film, e.g. full-size (24.times.36 mm) and half-size (24.times.18 mm).
As the frame size is changed from full-size to half-size the direction of the film carrier is shifted by 90 degrees, and the half-size film mask is set thereon. Next, the printing lens is switched to have an enlarged magnification (about two times for the full-size frame). In this condition an image of a half-size picture frame is printed as large as an image of the full-size picture frame on a photographic paper.
As photographic films are transported in a lengthwise direction within a camera and at a photographic processing apparatus (such as a film processor a film inspector, or a photographic printer), the photographic films tend to become scratched in their lengthwise direction. Therefore, it is important for a photographic printer to prevent photoprint quality from being degraded because of such scratches, and also efficiently to utilize light emanated from a light source.
In order to meet the first requirement a photographic printer has been proposed by the present applicant (U.S. patent application Ser. No. 07/356,109, U.S. Pat. No. 4,937,614 filed on May 24, 1989). In this photographic printer an anisotropic diffusion plate having a light diffusion property only in a direction perpendicular to the lengthwise direction of a photographic film, i.e., in the widthwise direction of a photographic film, is mounted between a light source and a photographic film. With this photographic printer, it is necessary to align the light diffusion direction of the anisotropic diffusion plate with the widthwise direction of a photographic film. Accordingly, when the transportation direction of a photographic film is changed by 90 degrees in accordance with a frame size, it is necessary to shift the anisotropic diffusion plate manually by 90 degrees, causing a cumbersome manipulation.